Ron Zook has had more valleys than peaks in his six seasons as Illinois coach. But he's riding a rare peak as he leads the Fighting Illini into spring drills.

Zook came close to losing his job after a 3-9 finish in 2009. It was Zook's fourth losing mark in five seasons, undoing any goodwill left from a magical and unexpected ride to the Rose Bowl after the 2007 season.

But a staff shakeup paid huge benefits in helping forge a 7-6 season that was capped by a Texas Bowl rout of Baylor, Illinois' first bowl win since toppling Virginia in the 1999 MicronPC Bowl.

Paul Petrino was brought in from Arkansas to coordinate the offense and Vic Koenning was tabbed from Kansas State to run the defense. Petrino's attack set school single-season records for points (423) and points per game (32.5). Koenning's unit excelled at big plays, ranking second in the Big Ten in turnovers gained (27), tackles for loss (6.2 pg) and sacks (1.8 pg).

But each has lots of work to do this spring. A feature running back must be found and Petrino needs to pump air into a passing attack that ranked 10th in the Big Ten and 111th in the nation (151.0 ypg). And for all the big plays that Koenning's group generated, the defense foundered down the stretch. The Illini allowed an average of 33.7 points (not including overtimes) in the last four regular-season games after yielding 16.7 in the first eight contests.

Compounding issues for both coordinators are some key personnel losses. No Big Ten school was hurt more by early departures to the NFL than Illinois. Running back Mikel Leshoure, defensive tackle Corey Liuget and linebacker Martez Wilson turned pro early.

Coordinator Paul Petrino had a huge impact on the offense in his first season in Champaign. His attack again should be formidable. QB Nathan Scheelhaase is back after hitting 58.7 percent of his passes for 1,825 yards with 17 touchdowns and eight interceptions in his first season as the starter. He also ran for 868 yards and five scores. Scheelhaase must become a better passer. Three starters are back from a line that helped the Fighting Illini pace the Big Ten in rushing (246.1 ypg). LT Jeff Allen and C Graham Pocic are standouts who should be among the best in the Big Ten at their position this season. Derek Dimke may be the top kicker in the Big Ten. He nailed a league-best 24 field goals last season (on 29 attempts).

Help is needed

In 2010, RB Mikel Leshoure ran for a school single-season record 1,697 yards -- second-most in the Big Ten -- but left a year early for the NFL. He was a workhorse who carried more times (281) than any Big Ten player. Burly Jason Ford (6-0/230) will get first crack at replacing Leshoure. Speedy Bud Golden, a big-play threat who needs consistency, and Troy Pollard will push Ford. The passing game needs to be amped up with more big plays. WR A.J. Jenkins is back after leading the team with 56 catches for 746 yards and seven touchdowns. A few more wide receivers must emerge, though TE Evan Wilson impressed as a true freshman and may be a future star. OT Corey Lewis, who sat out last year with a knee injury, is a projected starter. But he reinjured the knee in the offseason and likely will miss spring ball. The secondary was a mess last season, but three starters are back -- and presumably better -- and the unit will have a new coach in Mike Gillhamer, who coached safeties for the Carolina Panthers last season. FS Trulon Henry is the best of the bunch. The front seven suffered two big blows when T Corey Liuget and LB Martez Wilson turned pro early. No one on the roster comes close to matching the talent level of that duo. The defense also will miss LB Nate Bussey and E Clay Nurse. And a return game that has been horrid for years needs to improve.

3 guys to watch

LB Jonathan Brown: He could slip into Wilson's vacant spot in the middle or displace Ian Thomas on the weakside. Brown is a tremendous athlete, covers a lot of ground and has a nose for the ball.

DT Austin Tietsma: Tietsma, a redshirt freshman, has a chance to emerge as a playmaker on the interior of a line that has a huge hole to fill with Liuget gone early. But Tietsma, a standout prep wrestler, weighs just 242 pounds and must bulk up.

WR A.J. Williams: The coaching staff loves Williams' potential. Williams, a redshirt freshman, is a big target (6-4/202) who could be effective in the red zone and on third downs over the middle.

The pressure is on

RB Jason Ford: With Leshoure off early to the NFL, Ford has a clear path to the top job at running back. He has waited three seasons to be "the man" after arriving on campus amid great hype. Ford, who ran 99 times for 480 yards and seven touchdowns in 2010, needs to have a good spring and be more consistent in his attitude and effort. His weight has been an issue, but Ford has lost more than 15 pounds and is in good shape.

The buzz

Illinois has momentum for the first time since after the run to the Rose Bowl. It's vital for Zook to keep the ball rolling. There are some good building blocks on offense, led by a strong line and Scheelhaase. But the Illini must pass better and find a feature back. The defense has bigger issues, needing to replace four former starters in the front seven. But Zook's staff should be up to the task in what is a critical spring.